93 Rx7 Ls2 Project.

very nice work on the headers!

looking sick son

looking good.

Lookin’ good so far. :bigok:

looks great !

Any opinions on fuel pump wiring? I have dual walbros, should I wire them both to come on at the same time, or should I put one on a hobbs switch to turn on at like 2 psi.

if you have them come on seperately wouldnt you need to put a check valve in on of them?

I prefer to run both same time.

I think you will work them harder to have them both on the same time since you wont need the other pump until your approaching over 500whp. The pressure spike in the lines will be greater when they both turn on at the same time upon WOT hits. Running more pressure runs pumps harder. There shouldnt be as much of a pressure spike if you turn the second pump on at the right time its needed. Once one pump is maxed out, line pressure should start to drop off so thats time to turn on the second.
I have mine on a hobbs switch for 4-5 psi but wish it was like 7-8 psi since I am not over 500whp until about 7psi i’d guess. 12 made 640 running abit rich so i guess 6-8 psi is over 500whp. I’d run it on a hobbs switch if you can.

Wirin them together youwont get a spike. Mine are same time and don’t have any issues. Hobb switch can fail and then yourscrewed. Wiring them same is safer and is easier to tune since yolu remove any odd variable that can screw with ve vtable

any wiring can fail. You should see more pressure on stock sized lines if you hit both at the same time. I guess you can try turning the regulator down some to compensate. I just like the idea i can switch pumps for regular driving whenever i want to give the one a break for longer life i guess. I guess you can do the same with both on the same time when you go WOT. To each his own.

just run them both at the same time to simplify the setup, you’d need a hobbes switch and a check valve and yada yada. I have a dual 6 an to 8 an y block brand new if you need it.

I’m going to run without. One more thing that could fail and one less thing to install. Steve I already have the fuel system pretty much done, just waiting on my rails.

i seen a 8 psi rise from both pumps on at same time vs one. They make adjustable regulators for control of fuel pressure, you have to set your pressure anyways its no more effort to run them together then as you would one with a hobbs.

wiring can fail but if you wire them together and do it correctly if you lose a pump you just shut down. Let the motor open then replace then fuse and limp it home. Having one on hobbs you are relying on a switch that can fail and you have no idea it failed till you go into boost and your motor is done for.

using them together its much easier to dial the AFR in. Youre not working the pumps anymore then you would with one pump. Some like to think you heat up the fuel more by cycling more using two pumps but when you are in need of two pumps you also increase size of fuel carring lines, so the heat created by resistence from running them together isnt no where near as bad since youre lines are increase allowing more volume

im thinking of replacing my a1000 with walbros. how much can one support? i have seen cars run 3 but seems unnecessary. its time for my car to see more than 3 psi.

on a high pressure 255 you are looking at around 500 hp ballpark. Some have maxed them out making more hp, some less. If you want you could do the calculations about fuel supply. usually 2 walbros will handle what most people can dish out.

Single with boostapump kit can do 600 hp. CObra guys are doing that. I"ve seen several twin walbro kits with stock fuel hardlines do 1000+whp.

damn where hell you been? been wondering if anything going on with your car. you have been quiet all winter

ive been hibernating. i haven’t done anything to the car over winter. i took the t56 out a couple days ago and rebuilt it with a viper main shaft, billet syncro keys, steel 3-4 fork. the stock keys were laying in the case. this was my first t56 rebuild so i hope it stays together.

i will be contacting you soon for a roll bar. i dont think prp will let me run anymore with just lap belts and no bar.

glad to hear you are still working on it.